1. Technical Field
The invention relates generally to the sanitation of water in swimming pools and spas, and more particularly to an apparatus for use in isolating a source of sanitizing gas from the water being sanitized.
2. Background Information
Sanitizing water, in a spa for example, by the introduction of a sanitizing gas, such as ozone, serves to kill harmful microorganisms. It may be accomplished by generating the sanitizing gas as needed with an electrically powered generator, such as a conventional ozone generator, and coupling gas from this source over a supply line to the spa. For this purpose, gas bubbles may be entrained in a liquid pumped through a venturi to the spa in the manner described in U.S. Pat. No. 4,640,783 to Kern.
In doing this, it is important to guard against the passage of liquid back to the source where it might damage the generator or create a hazardous conductive path to the electrical power. In this regard, related Underwriter Laboratories specifications require the generator to be above the water level in the spa, and existing generators may be mounted at a point five feet removed from the spa for this purpose. With this technique, the relative height of the generator inhibits passage of liquid through the supply line back to the generator, and the distance of the generator from the spa limits exposure to water that may splash from the spa.
However, this arrangement involves the added cost and inconvenience of running lines to the generator and associated equipment. It may also be somewhat unattractive. Consequently, it is desirable to have a new and improved isolation system for a spa that alleviates these concerns--one that need not be located remote from and above the level of the spa.
A typical sanitizing gas generator, such as an ozone generator, simply provides the sanitizing gas, but does not provide it under pressure that would propel the gas from the generator to the desired location for utilization. Accordingly, as suggested by Kern U.S. Pat. No. 4,640,783, the sanitizing gas generator can advantageously be coupled to a suction line leading to the usual plumbing system for the pool or spa.
The suction line is under subatmospheric pressure, and the subatmospheric pressure may be created, for example, by pumping water or air through a venturi and coupling the sanitizing gas generator and the associated suction conduit to the throat of the venturi. The subatmospheric pressure at the throat of the venturi resulting from passage of the fluid through the venturi creates suction in the suction line sufficient to draw the sanitizing gas from the generator to the venturi where it is entrained in the water or air stream passing through the venturi.
Darrah, et al., U.S. Pat. No. 4,166,296, discloses a pressurized air supply system for a spa which includes an air blower for forcing air under pressure to the spa and a float valve between the air blower and the spa for draining water that may leak back to the float valve. This system is not usable in a vacuum or suction system for sanitizing gas because the suction would lift the float valve off of its seat and allow the escape of the suction pressure and the sanitizing gas.